Method for making an angle plug with looped conductor



J 1962 w R. FRANCIS 3,015,877

METHOD FOR MAKING AN ANGLE PLUG WITH LOOPEf) CONDUCTOR Filed Aug. 1,1957 W .1 y ndlaeo-az,

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United States Patent O 3,015,877 METHOD FOR MAKING AN ANGLE PLUG WITHLOOPED CONDUCTOR Wallace R. Francis, Milford, Conn., assignor to GeneralElectric Company, a corporation of New York Filed Aug. 1, 1957, Ser. No.675,647 2 Claims. (Cl. 29--155.55)

The present invention relates to electrical conductors and particularlyto a method for manufacturing an angle plug of an electrical cord of thetype used for connecting various electrical appliances to a plugreceptacle or convenience outlet. The majority of electrical cord setshave a standard attachment plug with contact prongs that are generallyparallel with the axis of the cord at the point where the cord entersthe plug. A modification of this is an angle plug where the cord entersa side of the plug so that the contact prongs or blades make an angle of90 with the longitudinal axis of the cord.

This invention was conceived with the idea of designing an angle plug sothe plug body will be of miniature size both for appearance and costreasons. While angle plugs in general are not new in this art, thepresent invention is an important contribution in the art of making suchplugs.

The principal object of this invention is to provide an improved methodfor manufacturing an angle plug of reduced size where the cont-actprongs or blades lie within the same plane as the cord, and theconductors of the cord are of such a nature that the contact prongs maybe assembled simultaneously thereto.

A further object of this invention is to provide an angle plug ofreduced size where the conductors at one end of the cord are cut off toan equal length and the surplus portion of one of the conductors isarranged so that it cannot short circuit the other conductor.

This invention is shown as it is embodied in an angle plug where theelectric cord enters one side of the plug body and the parallel contactprongs are arranged in a plane that includes the longitudinal axis ofthe cord where the cord enters the plug body. It should be understoodthat this invention is valuable even though the cord might enter oneside of the plug body at an angle less than 90". At the present timethere is equipment available for crimping a pair of contact prongs tothe bare conductors simultaneously. The present invention was conceivedwith the intention of using such equipment in order to hold the cost ofassembling this plug to a minimum. Accordingly, the cord will be cut tothe desired length and one end of the cord will have its insulationremoved the desired amount with the bare ends of the conductors cut tothe same length. Then an operator will insert the contact prongs into acrimping machine and place the ends of the bare conductors against theterminal ends of the prongs to crimp the prongs firmly on theconductors. The molding operation is next in the order of things and theconductor of one of the prongs is first looped by at least a full turnunder and around the other insulated conductor in order to shorten thefirst-mentioned conductor and position it in such a manner that it willnot short circuit the said other insulated conductor. This loop isnecessary because the parallel contact prongs are arranged in a planethat includes the axis of the cord and one contact prong is much closerto the cord-entrance side of the plug than the other prong.

My invention will be better understood from the fol lowing descriptiontaken in connection with the accompanying drawing and its scope will bepointed out in the appended claims.

FIGURE 1 is a front elevational view of an angle plug embodying myinvention attached to a short length of electric cord.

FIGURE 2 is a plan view of a two-conductor rip cord "ice having portionsof the insulation removed and a pair of contact prongs crimped to thebare conductors.

FIGURE 3 is a view similar to that of FIGURE 1 ex cept the plug body ismerely shown in dotted lines to illustrate the present invention oflooping a conductor of one of the contact prongs by at least a full turnunder and around the other insulated conductor.

FIGURE 4 is a view of a modification of FIGURE 3 where an electric cordof round cross-section is being used.

Referring in detail to the drawing, and in particular to FIGURE 1, thereis shown an electric cord 10 and an angle plug 11 having a pair ofcontact prongs or blades 12 for making engagement with the contacts of aconvenience outlet (not shown). The term angle plug is derived from thefact that the cord extends out of the plug body at an angle to thecontact prongs. As mentioned before, the standard type of attachmentplug has contact prongs which are generally parallel with the axis ofthe cord, as the cord enters the plug body. The subject. plug 11 is aspecial type of angle plug where the contact prongs 12 lie in a planethat includes the axis of the cord 10 as the cord enters the side of theplug body. In the majority of angle plugs'the axis of the cord isgenerally perpendicular to the plane that includes the parallel contactprongs. The present angle plug 11 represents a design of reduced sizeand improved appearance that is also lower in cost.

FIGURE 2 shows a two-conductor rip cord 13 where the electricalconductors 14 and 15 are cut to the same length, so the contact prongs12 may have their terminal ends 16 crimped to the bare conductorssimultaneously. The rip cord 13 is of standard construction, namely, twostranded conductors 14 and 15 with an oval shaped extruded rubber orvinyl insulating jacket 17 having upper and lower ripping grooves 18between the conductors to separate the conductors at the ends forconnection with an attachment plug or other electrical connector. Itwill be noted in FIGURE 2 that the insulation of the conductor 15 hasbeen cut back a greater distance than on the conductor 14. The reasonfor this will be understood after a study of FIGURE 3 wherein thecontact prongs or blades 12 have been arranged in a parallel manner withtheir flat sides facing each other.

The rip cord 13 enters the body of the angle plug 11 (shown in dottedlines) from the left side and the parallel prongs 12 lie generallywithin a plane that includes the longitudinal axis of the rip cord 13where it enters the plug body. Consequently, the left-hand contact prong12 of FIGURE 3 is closer to the cord-entrance side of the plug 11 thanis the other contact prong. Accordingly, the conductor 15 is longer thanneed be and something must be done with the surplus amount of conductorso it will not engage the other bare conductor 14 and create a shortcircuit. The present invention features the arrangement whereby theconductor 15 is looped by at least a full turn under and around theinsulated portion of the other conductor 14 thereby using up the surplusportion of the conductor 15 to prevent possible short circuiting betweenthe bare conductors. It should be understood that although the rip cord13 is shown entering the side of the angle plug 11 in a generallyvertical position with the conductors 14 and 15 in the vertical plane,the cord could also be turned fiatwise so that the conductors would liein a horizontal plane.

FIGURE 4 is a modification of the arrangement of FIGURE 3 in that around cord 20 has been substituted for the oval shaped rip cord 13 ofFIGURE 3. The round cord 20 has a pair of stranded conductors 21 and 22each of which are separately insulated as by the insulating layer 23 ofextruded rubber or vinyl. In the final step of manufacturing this cord arubber or vinyl jacket 24 is formed over the insulated conductors. Sincethe insulation 23 on the looped conductor 22 is somewhat 3 smaller indiameter than the insulation on the conductor 15 of FIGURE 3', it ispossible to leave the insulation 23 intact and loop the insulatedconductor 22 under and around theother insulated conductor 21.

Having described above my invention of a novel angle plug of reducedsize, it will be readily apparent to those skilled in this art that thecontact prongs may be assembled in pairs on the cords without dangerthat the conductors will short circuit across each other. Modificationsof this invention will occur to those skilled in this art and-it is tobe understood, therefore, that this invention is not limited totheparticular embodiments disclosed but that it is intended to cover allmodifications which are Within the true spirit and scope of thisinvention.

What I .claim as new and desire to secure by Letters Patent of theUnited States is:

1. A method for forming a solid angle plug on an integral two-conductorelectric cord comprising the steps of cutting each conductor of said twoconductor electric cord to substantially the same length, crimping acontact prong to each of said conductors simultaneously, looping theconductor of one prong at least a full turn under and around theconductor of the other prong, arranging said prongs parallel andopposite to each other and at substantially right angles to the axis ofthe cord, and molding an insulating plug body around the area of thecord which is crimped to the prongs.

'2. A method for forming a solid angle plug on an integral two-conductorelectric cord comprising the steps of cutting each conductor of saidtwo-conductor electric cord to substantially the same length, removinginsulation from one end of each of said conductors at one end of saidcord, crimping a contact prong to each of said conductorssimultaneously, looping the conductor of one prong at least a full turnunder and around the conductor of the other prong, arranging said prongsin parallel and opposite to each other and at substantially right anglesto the axis of the cord in a plane that includes the longitudinal axisof the cord, and'molding an insulating plug body around the area of thecordwhich is crimped to the prongs.

References Cited in the file of this patent UNITED STATES PATENTS2,284,392 Heiser May 26, 1942 2,502,860 Leithiser Apr. 4, 1950 2,700,206Gilbert Jan. 25, 1955 FOREIGN PATENTS 383,839 Great Britain Nov. 24',1932 528,037 Belgium Apr. 30, 1954 69,341 Germany Mar. 23, 1956

